I finally decided on Nyehquin's evolution

Torequiem, the cat-shark pokemon
Torequiem is a large water and dark-type pokemon that lives off the Osaigon coast, though occasionally they will come into the shallows to hunt. Their robust limbs and sharp claws make them deadly predators by land or sea. They clash with Arcanine for the best hunting grounds, and are powerful enough to prey on wailmer as they migrate up the coast.